Double-storey extensions · Stratford

Double-storey extensions in Stratford

Our double-storey extensions service covers Stratford and the rest of London. You get a fixed price in writing for the agreed specification, and one person co-ordinating the trades.

Covering Stratford

Our coverage around Stratford (E15) also includes Bow, Canning Town and Leytonstone.

Homes in London

Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.

What does a double-storey extension involve?

A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.

  • Measured survey, design and planning drawings
  • Householder planning application
  • Structural engineer’s design and calculations

What will a double-storey extension cost?

Typical ranges for double-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

Double-storey extensionsGuide price incl. VAT
Standard specification£2,400 to £2,900 per m²
Good specification£2,900 to £3,400 per m²
High specification£3,400 to £3,850 per m²

Do you need permission for a double-storey extension in Stratford?

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission.

What should I think about before starting?

  • Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
  • Neighbours’ light is assessed using the 45-degree guide many councils use.

What happens after I enquire?

  1. Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
  2. Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
  3. Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
  4. We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Your questions answered

Is a two-storey extension better value than a single-storey one?

Per square metre, usually yes, because the foundations and roof serve two floors of space.

Will we need to move out?

Most people stay. The noisiest stage is when we break through into the existing first floor, which we plan for a short window.

Who deals with the council for a project in Stratford?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Also covering

Learn more about double-storey extensions, or see every project we cover in Stratford.

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